#region Copyright (C) 2007 Jens Winter

//Copyright (C) 2007 Jens Winter

//This library is free software; you can redistribute it and/or
//modify it under the terms of the GNU Lesser General Public
//License as published by the Free Software Foundation; either
//version 2.1 of the License, or (at your option) any later version.

//This library is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//Lesser General Public License for more details.

//You should have received a copy of the GNU Lesser General Public
//License along with this library; if not, write to the Free Software
//Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using Flynn.Core;
using Flynn.Core.ExtensionMethods;
using Flynn.Core.ActivityResults;

namespace Flynn.Core.Activities
{
    public class FilterUpdatesActivity : IFilterUpdatesActivity
    {
        public FilterUpdatesResult FilterUpdates(Project project, string currentVersion, string targetVersion)
        {
            if (project == null)
                throw new ArgumentNullException("project");

            if (project.Updates.Count() == 0)
                return FilterUpdatesResult.Success(new List<Update>());
            else
            {
                string toVersion = string.IsNullOrEmpty(targetVersion) ? project.Updates.Last().Version : targetVersion;

                IEnumerable<Update> filteredUpdates;

                if (string.IsNullOrEmpty(currentVersion))
                {
                    filteredUpdates = from u in project.Updates
                                      where !project.Updates.IsVersion1YoungerThanVersion2(u.Version, toVersion)
                                      select u;
                }
                else
                {
                    filteredUpdates = from u in project.Updates
                                      where !project.Updates.IsVersion1YoungerThanVersion2(u.Version, toVersion) &&
                                            project.Updates.IsVersion1YoungerThanVersion2(u.Version, currentVersion)
                                      select u;
                }

                return FilterUpdatesResult.Success(filteredUpdates);
            }
        }
    }
}